Inositol derivatives: evolution and functions

Current research on inositols mainly focuses on myo-inositol (Ins) derivatives in eukaryotic cells, and in particular on the many roles of Ins phospholipids and polyphosphorylated Ins derivatives. However, inositols and their derivatives are more versatile than this — they have acquired diverse functions over the course of evolution. Given the central involvement of primordial bacteria and archaea in the emergence of eukaryotes, what is the status of inositol derivatives in these groups of organisms, and how might inositol, inositol lipids and inositol phosphates have become ubiquitous constituents of eukaryotes? And how, later, might the multifarious functions of inositol derivatives have emerged during eukaryote diversification?